Tonnage

Kamsarmax vs Panamax

Published 12 October 2026 · updated 13 October 2026

A Kamsarmax is a Panamax that grew. Both are gearless bulk carriers (ships with no cranes of their own) built to the beam of the old Panama Canal locks. The Kamsarmax is longer, at 229 metres, and carries about 82,000 deadweight tonnes. That puts it at the top of a class the Baltic Exchange describes as about 65,000 to 82,500. The market now treats the Kamsarmax as the standard ship of the Panamax class, which is why the two names are so often used as one.

The short answer

The deadweight ranges are trade conventions, not standards. The Baltic Exchange, which publishes the freight indices for these ships, puts "Panamax/Kamsarmax" in one line at "about 65/82,500 dwt, seven holds/hatches", usually gearless. It also warns that such terms "evolve quickly and they are not precisely defined". Brokers' reports differ by a few thousand tonnes at each edge. Deadweight is the weight a ship can carry, including cargo, fuel and stores.

Where each name comes from

Panamax is the largest ship that fits the original Panama Canal locks. The Panama Canal Authority's vessel requirements set the limits for those locks at a beam of 32.31 metres (106 feet), a length of 289.6 metres (950 feet) for most commercial ships, and a draft of 12.04 metres (39 feet 6 inches) in tropical fresh water. A bulk carrier does not need that much length to carry a Panamax cargo, so the beam was the limit that shaped the class. For a century, 32.31 metres was as wide as a ship could be and still take the short route between the Atlantic and the Pacific.

Kamsarmax comes from a berth, not a canal. Port Kamsar in Guinea is a loading port for bauxite, the ore that aluminium is made from. The terminal there is operated by Compagnie des Bauxites de Guinee, and the port guide FindAPort lists its maximum ship length as 229 metres. Shipbuilders kept the Panamax beam and stretched the hull to that length, which added cargo capacity without adding width. The name stuck to the design.

So the two names measure different things. Panamax is a width. Kamsarmax is a length. A Kamsarmax is both at once: Panamax in beam and Kamsar in length.

The Kamsarmax, as the Baltic Exchange describes it

The clearest public specification is the one the Baltic Exchange uses for its Panamax index. Its benchmark Panamax ship for time charter routes, read from its site on 12 October 2026, is a Kamsarmax in all but name:

The Baltic's weekly sale and purchase assessment for the class is also written as "Panamax (82,500 dwt)". When the benchmark for a class is the Kamsarmax, a Panamax rate quoted in a market report is a Kamsarmax rate. A smaller Panamax is not the ship the index describes, so its rate has to be worked out from the index and cannot be read straight off it.

The canal today

The Panama Canal opened a third, larger set of locks in 2016. The canal authority's limits for these Neopanamax locks are a length of 370.33 metres, a beam of 51.25 metres and a draft of 15.24 metres in tropical fresh water. The authority can lower the draft when the level of Gatun Lake falls.

A Kamsarmax fits the original locks in length and beam, but not in draft when fully loaded. To use them it must load less. By its published dimensions it fits the newer locks. This is why the word Panamax now describes a ship smaller than the canal it is named after, and why a canal transit on a laden Panamax is a question of the day's draft limit, not of the class name.

TFW is tropical fresh water and SSW is summer salt water. The two are not the same measurement. Fresh water is less dense, so a ship at the same weight sits deeper in the canal than at sea. Loadable quantity shows how a draft limit turns into tonnes of cargo.

What they carry

The Baltic Exchange guide to key trades says that the larger the bulk carrier, the fewer commodities it commonly loads. Capesize ships carry mostly iron ore, coal, bauxite and sometimes grain. Panamax sizes carry those cargoes and are also sometimes used for metcoke, petcoke, fertilisers, sulphur, salt, alumina and steel slabs.

The Baltic's own Panamax routes include a grain voyage of 66,000 tonnes from Santos in Brazil to Qingdao in China. The case for the bigger ship is simple: more tonnes on the same beam, where the ports at both ends can take it.

Both ships are gearless. They need shore cranes, loaders or floating cranes at both ends. That is the line between this class and the geared ships below it. Handysize, Handymax, Supramax and Ultramax covers the ships that carry their own cranes.

Which limit actually rules a ship out

A cargo enquiry rarely says Kamsarmax. It gives a quantity and two ports, and the ports decide. Three checks settle most cases:

• Length at the berth. A berth with a length limit below 229 metres takes a shorter Panamax and not a Kamsarmax. A ship that is a few metres too long for the load berth is not a candidate, whatever its class.
• Draft at both ends. A Kamsarmax earns its extra tonnes only where the water lets it load them. At a port with a draft limit, it may load no more than an older Panamax and cost more to run.
• Beam. Both ships share it. Above this class the beam widens, and the Baltic lists the next step, "Post Panamax/Mini Cape", at about 87,000 to 120,000 dwt.

So ask for length overall, beam and draft, not the class name. A search that filters on the name misses ships described the other way. Matching cargo to tonnage sets out the full order of checks, and dry bulk vessel sizes places this class among the others. In the register behind this site, 5,112 ships fall in the 65,000 to 99,999 dwt band that holds both.

To see what the extra cargo is worth on a given voyage, run the same freight rate at both quantities in the free TCE calculator.

Where the sources disagree

• The deadweight edges. The Baltic's general guide groups Panamax and Kamsarmax at about 65,000 to 82,500 dwt. Its index benchmark is one ship of 82,500. This site files everything from 65,000 to 99,999 under Panamax so that a search does not miss a ship at the edge. None is wrong. They are conventions, and each is drawn for a purpose.
• The lock length. The canal authority's own notice gives 289.6 metres for most commercial ships and a longer figure for passenger and container ships. A bulk carrier is far shorter than either.
• Kamsar itself. The 229 metre figure is the published berth limit. Port limits change with dredging and new berths, so check the current restriction with the agent before fixing a ship for Kamsar.

References

• Baltic Exchange, Guide to Modern Shipping: Main Types of Vessels, read 12 October 2026. balticexchange.com
• Baltic Exchange, Dry market information: Baltic Panamax vessel description, read 12 October 2026. balticexchange.com
• Baltic Exchange, Guide to Modern Shipping: Key Trades, read 12 October 2026. balticexchange.com
• Panama Canal Authority, OP Notice to Shipping No. N-1-2024: Vessel Requirements, 2024, section 2. pancanal.com
• Shipping Guides Ltd, FindAPort: Port Kamsar, read 12 October 2026. findaport.com

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